Oil and water

Just something I was mulling over this weekend.
If both components pass over/through the same material (engine) is it not correct to assume that both should register the same temperature. If not
why not.
Or are both monitored at different stages of flow.
dj oil temp on cool day (15/20c) = 80C while water = 90C
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The water is there for the specific purpose of removing excess heat from the engine. For this reason it passes as close as possible to the sources of the greatest heat - around the combustion chambers, the cylinder head and cylinder bores. The oil has the primary purpose of lubricating the moving parts of the engine - in particular, the crankshaft bearings. Some oil does go to the head, to lubricate the valve gear and some is sprayed onto the cylinder walls but not, necessarily, close to the heat sources, and not in vast quantities.
--
Peter Bell - snipped-for-privacy@bellfamily.org.uk

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
hmmmm, oil splashed up the bores must touch the underside of the pistons. These being aluminium the oil must be close to combustion chamber temps.
Aluminium is a first class conductor of heat.
I suppose my temps are close enough for the theory to stand.
thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes, but only relatively small quantities of the oil.
--
Peter Bell - snipped-for-privacy@bellfamily.org.uk

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Also the oil is not cooled down as well as the water. It's not necessary since the oil works fine in much higher temperatures. In my Audi the oil is cooled (and preheated for that matter) close to the oil filter. At certain speeds (revs) the oil and water are both 90 degrees Celsius.
Ronald
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

yes when it's 30C ambient both of mine are 90C
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Also, oil and water have quite different Specific Heat Capacity values. SHC is the amount of energy in joules, required to raise one gram of the substance by one degree kelvin.
Liquid water is 4.186 joules, I expect engine oil is higher.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

liquid water..........is there any other.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Ice & steam?
--
Peter Bell - snipped-for-privacy@bellfamily.org.uk

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

And snow and vapour? ;o)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Lez Pawl" wrote

Not an answer to your question, but I'm just curious, where are you getting the water temp info from? Hopefully not from the water temp gauge in the dashboard, as that thing is programmed to stay right on 90C regardless whether the coolant temp is 90C or 80C or 100C.
Cheers, Pete
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

what rubbish..........on a very cold day, -7C ambient the water temp only gets to 80C.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Ronald
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"R@L" wrote

Let me be more specific. The coolant gauge on my '01 A4 behaved that way. It had a dead range in the center, and it was designed to stay there and not alarm the driver if it was a few degrees below or above 90C. Maybe it was betw. 85C and 95C, I can't remember. Only if something was seriously out of whack (big temp change) would the gauge move to the left or right of the center. This could be easily monitored on the digital coolant temp display in the climate control section - the temp would fluctuate a few degrees here and there while the needle on the dashboard would not budge from the center.
Cheers, Pete
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote

now you are comparing analogue against digital and a few degrees...........come on. The analogue gauge will not be mega bucks so I would expect it to be +/-5 degree anyway.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"Lez Pawl" wrote

You're not hearing what I'm saying. If this is a problem with you not believing me, just go onto the B5 A4 forum on AudiWorld - everyone will confirm that the coolant temp gauge on those cars has a dead range.
Cheers, Pete
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.